Stoker



P. A. KETCHPEL 2,015,526

STOKER Filed Nov. 2, 1931 S'SheetS-Sheet l- Sept. 24, 1935.

IN VEN TOR.

ATTORNEY.

Sept. 24, 1935. P. A. KETCHPEL 2,015,526

STOKER Filed NOV. 2, 1951 3 Sheets-Sheet 2 INVENTOR. y

ATTORNEY.

Sept. 24, 1935. P, A; KETCHPEL 2,015,526

STOKER Filed Nov. 2, 1931 3 Sheets-Sheet 3 INVENTOR ATTORNEY PatentedSept. 24, 1935 PATENT OFFICE STOKER.

Paul A. Ketchpel, Bergenfield, N. J., assigner to The Standard StokerCompany, Incorporated, a corporation of Delaware Application November 2,1931, Serial No. 572,610

4 Claims.

'Ihis invention relates to improved stoking mechanism for firingfurnaces, particularly furnaces of the type in which the rebox grate 1scomparatively wide with respect to the depth' yI thereof, and moreparticularly to stoking mechanism for firing furnaces of marine boilers.

In marine service it is common practice to use furnaces of the typehaving comparatively wide but short firebox grates. Furnaces of thistype l0' are provided with a number of openings spaced apart along thefront, through which fuel is delivered to the firebox. In manual ring ofsuch furnaces it is impossible to maintain an even distribution of fuelover the lire since it is physically impossible for the fireman to firethrough the several openings simultaneously.

In manual firing it is the practice to cover the live re with a largeexcess of green coal and when it has burned through add another largeexcess of green coal. There is as a resulta great fluctuation in boilerpressure and a large loss of eiiiciency. Repeated opening of the fireboxdoor for hand firing furthermore admits an excess supply of cold airover the re with consequent decrease in efliciency of fuel combustion.

Furnaces of the type described are extremely diiiicult to re bymechanical means and it is an object of this invention to provide asimple and efficient mechanical stoking arrangement which will maintainan -even and continuous distribution of fuel over the entire firebox.

It is a further object of this invention to provide a mechanical stokingarrangement, in furnaces of the type described, which Will permiteicient delivery of fuel thereto without interfering with the handfiring and the inspection, cleaning and repair of the boiler andfurnace.

Other and further objectsand advantages of the invention will beapparent from the description when viewed in the light of theaccompanying drawings, in which Fig. 1 is a side elevation of theinvention as applied in a marine installation with portions of the fuelbunker and furnace room shown in section;

Fig. 2 is a partly diagrammatic fragmentary plan View showing theinvention as applied on the left side of the furnace and fuel bunkerwith 5o portions of the fuel bunker and furnace room shown in section;

Fig. 3 is a detail View of the fuel distributing arrangement of Figuresl and 2;

Fig. 4 is a detail View of an elbow for deliver- 55 ing fuel to thefurnace;

Fig. 5 is a modified form of the stoking arrangement;

Fig. 6 is a detail view of the fuel delivery elbow of the modificationshown in Fig. 5, and

Fig. 7 is a plan view of the structure shown 5 in Fig. 1.

The preferred form of the invention, illustrated in Figures 1 to 4inclusive, Will be described as applied in a marine installation, thoughit will be obvious that the invention is also applicable 10 in otherfurnace installations.

The bottom wall of the hull of a vessel is shown at I0, and the deck ofthe furnace room at II. The furnace is designated generally by thenumeral I2 and comprises the iirebox I3, grates I4, 15 front wall I5 andsidewalls I6. spaced at intervals along the front wall I5 of the furnaceare the usual hand firing openings I'I, the number depending on thewidth of the furnace.

The fuel bin is shown at I8 and is provided 20 with the floor I9constituting a continuation of the deck I I. 'I'he floor I9 is providedon each side with a longitudinal opening 20. Located between the fuelbin floor I9 and the bottom wall Il of the vessel and communicating withthe fuel bin 25 I8 through the opening 20 is the open mouthA troughmember 2|, forming the rearward portion of the fuel transfer conduit 22.The forward portion of the fuel transfer conduit 22 is formed by thetubular conduit section 23, constituting an extension of the troughmember 2l. Slide plates 2d are sldably mounted in the marginal edges ofthe floor I9 bordering the opening 20, so that they may be moved touncover or cover the opening 20 in a manner to control the delivery offuel to the trough member 2l.

Conveyor screw 25 is mounted in the transfer conduit 22 for advancingfuel forwardly therethrough. Rearward of the trough member 2I andextending transversely beneath the fuel bin floor I9 is formed thecompartment 26. Housed within the compartment 26 is the gearing 2l anddrive shaft 28 for operating the conveyor screw 25. The drive shaft 28is operated by 45 the motory 29, mounted at one side of the fuel bin andbeneath the deck II. Access to the motor 29 and the compartment 26 maycon-y veniently be had through the door 30 in the deck II.

The furnace I 2 is provided with the opening 3l through the sidewall I6adjacent the front Wall I5, at a suitable height above the level of thegrates I4 for scattering fuel in aerial paths thereover. Riser conduit32 extends upwardly and 55 forwardly from the forward end of thetransfer conduit 22 and communicates at its upper end with the opening3|. Conveyor screw 33 mounted in the riser conduit 32 is universallyconnected with the transfer conveyor screw 25, as at 34, and deliversfuel to the opening 3|.

The upper end of the riser conduit 32 terminates in the inwardly anddownwardly curving elbow 35. The elbow 35 is provided with the flange 3efor attachment to the marginal edges of the furnace wall bordering theopening 3i, by suitable means, as bolts 3l. Formed with the elbow 35adjacent the bottom of its delivery end is the chamber 38. The chamber38 is divided into any desirable number of compartments 33, and pressurefluid is delivered to the compartments 39 from a suitable source, asfrom the boiler, through the pipes 4E). The pipes 40 connecting with thecompartments 39 may be controlled by valves. Pressure fluid is emittedfrom the compartments 3S through any suitable number of jet openings 4i.A quadrant shaped distributor plate l2 extends forwardly from the lowerforward end of the elbow 35, and carries diverging ribs 43 on its uppersurface for spreading the fuel over the firebed.

The invention has been described with reference to that portion of thefuel bin and furnace to one side of its longitudinal center line, but

it will be understood that the other side is similarly equipped withfuel conveying and distributing means so that the stoking arrangement onthe one side of the furnace and fuel bin is the exact counterpart of thestoking arrangement on the other side thereof.

By admitting fuel to and distributing it from the corners of the rebox,a more complete utilization of the effective grate area is obtained. Thecorners of the lrebox are never as effective heat producing areas as theother parts of the flrebox since they are difficult to fire properly;therefore by utilizing these `less effective heat producing areas toaccommodate means for introducing the fuel into the rebox, the moreeffective parts of the rebox area may be maintained unobstructed by fueldelivery and distributing mechanism. With the present improvedarrangement for delivering fuel to furnaces of the type described, theamount of coal particles and cinders carried into the flue is minimized,since ,the greatest part of the fuel is projected at an angulardirection with respect to the direction of the draft.

Each of the conveying and distributing systems delivers fuel to andscatters it uniformly over a half of the grate area. By delivering thefuel through the sides of the furnace in the direction of its longestdimension, it is possible to uniformly distribute fuel over the gratewith a minimum number of delivery points.

In Figures and 6 is illustrated a modified form of the invention inwhich fuel is delivered from a bin (not shown) to a hopper 44 located atthe front of the furnace midway between the sidewalls it. A tubularconveyor conduit 45 extends horizontally along the front wall I5 of thefurnace and is provided with an opening communicating with the bottom ofthe hopper 44. A screw conveyor 45 is rotatably mounted in the conduit45 and is provided with the oppositely inclined flights il and 48. Theflight 41 is arranged to convey fuel to the left side of the furnace andthe flight 48 is arranged to convey fuel to the right side of thefurnace. The screw flights 4l and 48 are provided at their opposite endswith the blade-like ends 4S for pushing the fuel at right angles to thedirection of the conduit. The conduit 45 terminates at each end in adownwardly and inwardly curving elbow 50 arranged to deliver fuel to thefurnace through 5 the openings 5i in the sidewalls of the furnaceadjacent the front wall l5. A slide gate 52 at the bottom of the hopper44 is provided so that the amount of fuel delivered to the conduit 45may be conveniently regulated and controlled to deliver more or lessfuel to one side than the other. In operation fuel is delivered to theconduit 45 from the hopper 44 and is conveyed to the elbows 5f) by thescrew conveyor 46. It passes through the elbows 5G into the rebox i3 andis 15 scattered over the fire in the same manner as described in thepreferred form of the invention.

I claim:

l. In combination with a furnace having a front wall, sidewalls and agrate surface of greater width than depth, a fuel bunker, a single fueladmission opening in each of said sidewalls adjacent said furnace frontwall, a pair of fuel transfer conduits at opposite sides beneath andcommunicating with the fuel bunker, a pair of riser conduits extendingupwardly and forwardly from the forward ends of said transfer conduitsto points adjacent the tops of said openings, each of said riserconduits terminating in a downwardly and inwardly curving elbow, each ofsaid el- 3'0' bows extending into a respective opening, a screw in eachof said transfer conduits advancing fuel to said riser conduits, a screwin each of said riser conduits for elevating fuel to said elbows,

and a fuel distributing plate arranged at each of said openings toreceive the fuel dropped by gravity through said elbows.

2. In combination with a furnace having a front wall, sidewalls, a reboxand a grate surface of' greater width than depth, a fuel bunker, 40`

a single fuel admission opening in each of said sidewalls adjacent saidfurnace front wall a sufficient distance above the level of the grate topermit scattering fuel in aerial paths thereover, means for deliveringfuel from said bunker to said openings including a pair of transferconveyors receiving fuel from the bunker and eX- tending forwardlytherefrom, a pair of elevating conveyors extending upwardly andforwardly from said transfer conveyors to the upper portion of saidopenings, each of said elevating conveyors terminating at its upper endin a .downwardly and inwardly curving elbow, each of said elbowsextending into a respective opening, and a quadrant shaped 55distributor plate in each of the front corners of said firebox at thedelivery end of each elbow.

3. In combination with a furnace having sidewalls, a front wall and agrate surface of greater width than depth, a source of fuel supply, asingle fuel admission opening in each of said sidewalls adjacent saidfront wall, mechanical means for conveying fuel from the source ofsupply to said openings, said means including a pair of conveyingelements, each receiving, fuel from the source of supply and deliveringtoward its respective opening in a sidewall, downwardly and inwardlycurving elbows each receiving fuel from the discharge end of itsrespective conveying element and delivering to its respective open- 70.

wardly and inwardly curved elbow, a pressure uid lead communicating withsuch chamber, and a wall at the delivery end of said elbow provided withjet openings leading. from said chamber and arranged to issue blasts ofpressure fluid over the iirebed.

4. In combination with a furnace having side walls, a front wall and agrate surface of greater width than depth, a source of fuel supply, asingle fuel admission opening in each of said side walls adjacent saidfront wall, mechanical means extending across said front wall forconveying fuel from the source of supply to said openings, said meansincluding a pair of conveying elements, each receiving fuel from thesource of supply and delivering toward its respective opening in a sideWall, downwardly and inwardly curving elbows each receiving. fuel fromthe discharge end of its respective conveying element and delivering toits respective opening, and a fuel distributing member at each of saidopenings receiving fuel from its respective elbow and scattering thefuel over the flrebed, each distributor member including a chamberformed beneath the bottom wall of the downwardly and inwardly curvedelbow, a pressure fluid lead communicating with such chamber, and a wallat the delivery end of said A elbow provided with jet openings leadingfrom said chamber and arranged to issue blasts of pressure fluid overthe rebed.

PAUL- A. KETCHPEL.

